If bumblebees were to die out, it would be a tragedy and an environmental disaster

Dr Dave Goulson

Their numbers have been falling in recent years, largely due to intensive farming practices.

Dr Dave Goulson, a senior lecturer at the University of Southampton, says the picture is serious.

"The last 50 years have seen hedgerows ripped up, and most of the flower-rich grasslands once used for grazing have been reseeded with rye grass.

"If bumblebees were to die out, it would be a tragedy and an environmental disaster. They are major pollinators of wild flowers.

"If the bees disappear, the plants will set fewer seeds and may themselves vanish."

Economic impact

In Chichester, less than 80 kilometres (50 miles) from Southampton, Gerry Hayman inspects a vast glasshouse of tomato plants.

Bees are used to pollinate commercially-grown tomatoes

Over a site covering nine hectares (23 acres) more than 1,000 tonnes of the fruit are growing here at any one time.

The humble bumblebee plays a critical role. In all, 8,000 buzz around - pollinating the whole crop.

"None of our bees are taken from the wild, they're bred and imported from Holland. We use them to pollinate the plants," says Mr Hayman, chief scientific officer for the British Tomato Growers' Association.

"Years ago, the job was done by hand - growers would tap each plant individually to loosen the pollen. It was a laborious and time-consuming job.

"If numbers were to decline it could have a serious economic impact on the industry."

Genetic fingerprint

Because the insects' colonies are largely underground and hard to find, conservationists have problems assessing the state of the various species.

Dr Goulson has developed a technique to catch the bees and conduct a DNA analysis.

Can genetic technology save the bumblebee?

They are trapped in nets and a miniature hypodermic needle is used to remove a tiny amount of the bee's equivalent of blood, which carries a genetic fingerprint.

''Individuals from different nests are not visually distinguishable, but the DNA analysis allows us to tell them apart," says Dr Goulson.

"By identifying which bees are sisters - and therefore from the same nest - it should be possible to determine just how many separate nests there are in an area.

"If we know in which parts of the country they still have strongholds, we can determine what types of land-use suit them best."

The future of a whole host of crops from oil seed rape, strawberries and apples as well as wild flowers could depend on the research and the plight of the bumblebee.